Automatic control for aircraft, etc.



J. S. MORRISON AUTOMATIC CONTROL FOR AIRCRAFT, ETC

June 20, 194.4.

6 Sheets-Sheet 1 Filed Aug. 14 1959 llifilt 0 O 3 M W W 9 3 MN Q June20, 1944. .1. s. MORRISON 2,351,694 AUTOMATIC CONTROL FOR AIRCRAFT, EEC

- Filed Aug. 14, 1939 6 Sheets-Sheet 2 g /.LaaP

Oscamnw 50/0 I QOMPASs Z 7 %WM/ June' 20, 1944.

J. s. MORRISQN AUTOMATIC CONTROL FOR AIRCRAFT, ETC

Filed Aug. 14, 1939 6 Sheets-Sheet 5 6 Sheets-Sheet 4 J. s. MORRISONAUTOMATIC CONTROL FOR AIRCRAFT, ETC Filed Aug. 14, 1959 June 20, 1944.

1 June 20, 1944.,

J. s. MORRISON AUTOMATIC CONTROL FOR AIRCRAFT, ETC

Filed Aug. 1 6 Sheets-Sheet 5 June 20, 1944. J. MORRISON 2,351,694

AUTOMATIC CONTROL FOR AIRCRAFT, E110 Filed Aug. 14, 1939 6 Sheets-Sheet6 producethe most advantageous result.

Patented June 20, 1944 AUTOMATIC CONTROL FOR AIRCRAFT, ETC.

Jess S. Morrison, Southgate, Calii'., assignor to Leo M. Harvey, LaCanada, Calif.

Application August 14, 1939, Serial No. 291,478

12 Claims. (01. 244-78) This invention relates to the control of aircraft, vessels, vehicles, etc. and relates more particularly to anautomatic pilot, or control means, for the control of air craft, landand sea craft, torpedoes, etc. A general object of this invention is toprovide a practical, dependable and very effective automatic pilot orautomatic control of the character mentioned.

Another object of this invention is to provide an automatic pilot orcontrol that may be governed by directional radio circuits, gyroscopes,mercury switches, or other suitable sensitive means, and thatis suitablefor the control of the steering rudder or other control part fordirectional control, the elevator for altitude control, the ailerons forlateral control, auxiliary surfaces for trimming the craft or for thecontrol of any other steering or control part of the craft, vessel, orvehicle.

Another and important object of the invention is to provide an automaticpilot or control of the character mentioned that is responsive to and.is adapted to be controlled by any selected radio broadcast to maintainthe craft on the course as defined by broadcast.

Another object of this invention is to provide an automatic pilot. orcontrol of the character mentioned that is useful as an optional controlmeans being quicklyputdnto operation where blind flying .is desired orrequired, or where the pilot is fatigued or otherwise disabled, andbeing quickly and readily made inactive and fully re,- leased from thecontrol surface or element of the craft so that the craft may be underthe full control of the operator or pilot without drag or resistance bythe automatic control means.

Another object of this invention is to provide an automatic pilot thatis very light in weight and compact, particularly adapting it for use onaircraft, etc.

Another object of this invention is to provide an automatic pilot of thecharacter mentioned that moves or advances the rudder 'or other controlpart of the craft or vessel in a manner to Another object of thisinvention is to provide an automatic control or plot for air craft,etc.-, that is constructedto be easily serviced and repaired. The deviceor control of the present invention may be easily repaired andserviced'by persons ormechanics without special training. A furtherobject of this invention is to provide an, automatic pilot of thecharacter mentioned that 'is inexpensive to manufacture and install.

The various objects and features of my invention will be fullyunderstood from the following detailed description of a typicalpreferred form and application of the invention, throughout whichdescription reference is made to the accompanying drawings, in which:

Fig. 1 is a diagrammatic view of the automatic pilot or control ofthepresent invention showingthe various elements or units of the control inperspective and in spaced relation. Fig. 1' is an enlarged verticaldetailed sectional view of the connection between the rack and thereleasable vertical detailed sectional view taken as indicated by line6-6 on Fig. 4. Fig. '7 is an enlarged, fragmentary, vertical detailedsectional view takenas indicated by line 1-'i on Fig. 4. Fig. 8 is anenlarged detailed sectional view taken on line 88 on Fig. 7. Fig. 9 is aside view of one of the links of the ratchet means.

The automatic control or automatic pilot of the present invention may besaid to comprise,

generally, operating means A connected with the rudder, elevators, orother control surface or part of the craft, means B operable to advanceor operate the means A in either direction, reversible power means C foroperating the means B, an automatic control D for the power means C,restoring means or timer means E associated with th control D andoperable to cause the power means C to intermittently or repeatedlyactuate the means B, and means F for releasing the means B,orfonrenderlng. the means B 'inactive.

The means A is connected with the part of the craft, vessel, or vehicleto be operated or governed. As above pointed out the automatic controlor pilot ofthe invention is useful for operating or controlling vehiclesand vessels of various natures and is suitable for the operaiion ofsteerring, stabilizing, and elevating parts of practically any kind. Themeans A may be arranged and constructed for connection with and for theoperation of controlling and steering parts of different kinds. In thetypical, case illustrated it may be considered that the means A isconnected with'the vertical rudder or directional rudder (not shown) ofan air craft. In Fig. 1 I-have shown a portion of a stem or rod ill thatmay be I considered as extending to and connected with the rudder.

The means A includes a longitudinally shiftable or reciprocable elementin the nature of a toothed rack H releasably operatively connected withthe rudder .rod ii A link 42 serves to operatively connect the rack Hwith the rod iii and is releasable 'by the operator to free the rudderrod from the automatic control mechanism. The inner end of theconnecting link I 3 is plvotally connected with the rack H. A yoke i3 isprovided on the inner end of the link l2 and receives the adjacent endportion of the rack ii. A pivot pin it connects the yoke 13 with therack H. A roller is is arranged in-the yoke i3 to cooperate with pitchedfaces i3 and ill on the end of the rack ii. The shaft i3 01 the roller lshifts in slots IS in the yoke i3 and springs are connected with theroller shaft iii to urge the roller against the pitched faces l3 andiii.

A hook 2B is provided on the outer end of the link 12 to cooperate witha pin 22 carried by a. collar 23 fixed to the rod i0. When the link i2is in its normal position substantially parallel with the rack i i thehook 2i cooperates with the pin 22 and the roller i5 bears against thepitched surface H to releasably retain the link in place. The hook 2icooperating with the pin 22 is operable to transmit movement between thelink l2 and the rudder rod 90. A remote control is provided forreleasing .the hook 2!! from the pin 22 to disconnect the automaticpilot mechanism from the rudder rod 53. A cable or line is connectedwith the link l2, and extends to the instrument panel25 where it isprovided with a readily accessible operating ring 28. When the ring 26is pulled the link I2 is raised to release the hook it from the pin 22.This brings the roller' l5 into cooperation with the pitched face I6 andthe spring held roller cooperating with the face it retains the link H2in its raised released position. stops 2? are provided on the rack II tostop the link H2 in its two positions; Guides 28 may be-provided on thecollar 23 to guide the hook 2! to the pin 22. The hook 2i normallycooperates with the pin 22 to connect the automatic pilot means with therudder or control rod Ill and is only' released in an emergency or inthe event that the automatic pilot means fails or jams. It is to beunderstood that .the linkage between the rudder or control part of thecraft and the rack Ii may include universal joints, direction -changingconnections, etc. as may be required.

The rack I l of the means A extends into a box or case 30 where it issupported for free reciprocable movement. The rack ll may b carried andguided by spaced flanged rollers 3l.supported by horizontal shafts 3 2.The shafts 32 are carried inv openings in spaced supporting plates 33mounted in the case 30. With the rack H arranged as just described, itsteeth 34 extend along its upper side. The series of rack teeth 34 ispreferably of substantial length.

The means B is provided to move or operate the rack H in eitherdirection for the, control of ,the rudder rod or control rod Ill. Themeans 13 is in the nature of a releasable double acting ratchet and gearmechanism operated by the power means C and geared to the rack l I. Inthe construction illustrated the'means B includes a shaft 35 disposed atright angles to the rack II and rotatably supported in the case 30 bythe spaced .plates 33. A pinion or gear 36 is freely tumable on theshaft 35 and meshes with the rack ii. A ratchet wheel 3? is fixed to orturn-' means C as will be later described. The upper.

arm of the rocker 33 is provided with an arcuate slot 30 and a reducedhead ii above the slot. oppositely directed dogs or pawls 62 aresupported in side by side relation on a pin 43 pro- Jecting from therocker 33 above the slotdil. Springs Ml act on the pawls #32 to urgethem downwardly and inwardly toward the wheel 31. The points or blades:15 of the pawls 62 are shaped for cooperation with the teeth 38 of thewheel 31. A pin 66 is fixed to the adjacent supporting plate 33 andpasses through the slot (iii of.the rocker 33. The pin lii carries afreely rotatable roller ll which cooperates with the lower edges of thepawls 12. With the rocker 33 in its normal vertical or neutral positionthe roller i'i cooperates with the two pawls 62 to hold them releasedand spaced from the ratchet wheel 3?. When the rocker 33 is pivoted bythe power means C the axis of the pawls 62 moves relative to the fixed VThe blade :35 of the pawl 62 cooperates with a is adapted to be swung inopposite directions by the power means C and the pawls 632 face inopposite directions to impart clockwise and counter-clockwiseturningmovement to the ratchet wheel 3fl. Y

The means B further includes holding dogs 81 fol-preventing return orreverse movement of the ratchet wheel 37. When the automatic pilot orcontrol is in operation to move the crafts' control surface or part in agiven direction the rocker 39 oscillates in such a manner that a pawl 42intermittently turns the wheel 31 to advance or move the rod I!) in agiven direction. The' rocker 33 oscillates between a partially turnedposition and a fully turned position so long as the operation continuesand when the control sur face or part of the craft has been brought to aposition to return the craft to its course or intended position therocker 33 returns to its normal vertical position. The dogs 81 arecooperable with the teeth 38 of the Wheel 31 to prevent reverse turningof the wheel by the pawls d2 during the return movements of the rocker39 and to prevent the action of external forces on the rudder or controlpart of the craft from reversing the rudder or control part. The dogscry of the wheel31 and the dogs are provided with bevelled teeth, .orblades 99 for cooperating with the ratchet wheel 'teeth 38. One dog 91is positioned to prevent clockwise turning of the wheel 31 and the otherdog is arranged to prevent counter-clock-wise turning of the wheel.

The ratchet dogs 91 are interconnected with the rocker 39 to becontrolled by movement of the rocker.- Angular or arcuate links 9| areconnected with the dogs 91 by pivot pins 92 and" extend upwardly andtoward one another. The links 9| are. provided with elongate arcuateslots be driven by an auxiliary power drive or by an air driven blade inthe slip stream of the craft. For the sake of simplicity I haveillustrated a Venturi tube 49 as the source or generator of negativepressure for the operation of the power means C, itbeing understood thatother means may be employed for this purpose. The Venturi 93 whichreceive or pass a pin 94 provided on the rocker head 4|. The upperportions of the links 9| are in side by side relation so that the pin94'may pass through their registering slots 93. The springs 89 tend topivot the dogs 91 inwardly toward the ratchet wheel 31 and tend to drawthe links 9| downwardly. The parts are related so that the upper ends ofthe slots 93 cooperate with the pin 94 when the rocker 39 is in itsnormal position and this cooperation holds the dogs 81 in releasedpositions where their blades 99' are free of the ratchet teeth39.

Upon swinging of the rocker 39 to the right the pin 94 tends to moveaway from the end of the slot 93 in therighthand link 9| and the spring89 draws the link downwardly so that it follows or moves with the rockerand the spring pivots the righthand ratchet dog 91 to bring its blade 99into engagement with the ratchet teeth 39. The ratchet dog blade 99comes into cooperation with the ratchet wheel teeth 38 before the blade45 of the righthand pawl 42 comes into moving en-- the wheel being heldby the ratchet dog 91. During a phase of operation of the mechanism therocker 39 does not return to its normal vertical position but remainspartially pivoted to the right or left as the case may be. so that thedog 91 remains in cooperation with the ratchet wheel 31 to preventreversal of the wheel .by the action of the air flow or external forceon the rudder or control part of the craft. The rocker 39 may berepeatedly swung between the partially turned position and a fullyturned position to intermittently turn the wheel 31 and the ratchet dog91 remains in efiective engagement with the ratchet wheel throughoutthese operations. When the craft has returned to its course or intendedtoits'released position. When the rocker 39 is operated in the lefthanddirection the mechanism operates as described above, and the lefthanddog 81 serves to prevent a reversing or clockwise turning of the wheel31.

tube 49 maybe arranged in the slip stream or otherwise located to handlethe air flow resulting from the craft's movement. A main negativepressure channel or line 59 leads from the throat of the Venturi tube 49to the power means C.

It is preferred to inter-pose a negative pressure equalizer orstabilizer in the main line 59 to maintain a substantially uniformcondition in the line. This device may comprise a bellows 5| whose sidesare urged apart by a spring 52. An air inlet 53 in one side of thebellows 5| is controlled by a spring held valve 54. The valve 54 carriesan adjustable screw 55 engageable with a post 55 on the other side' ofthe bellows 5| to cause opening of the valve 54 when the differentialbetween the atmospheric pressure and the negative pressure becomesexcessive. The interior of the bellows 5| is. of course, incommunication with the line 59 and in practice the line 59 may enter theopposite sides of the bellows. The bellows is preferably suitablymounted in the case 39. A negative pressure meter M may be connectedwith the line 59 and positioned to be readily visible.

The motor or power means C comprises a pair of opposed diaphragm unitswhich I will term bellows 56'. The diaphragms 51 of the bellows 55 areconnected for movement in unison by a connecting rod 59. The bellows 55are suitably mounted in the case l9. for example, they may be supportedon the plates 33. A vertical shaft 59 extends between the spaced bellows59 and is suitably journaled in'the case 39. An arm 59 is fixed on theshaft 59 and has a yoke 3| engaged by a pin 62 on the connecting rod 59so that the shaft 59 is turned by the bellows 56. A head 63 on the pin62 cooperates with the yoke 6| to prevent disengagement of the yoke fromthe pin.

It will be seen how movement of the bellows diae phragms 51 producesturning movement of the shaft 59. An arm 54 is fixed to the lowerportion of the vertical shaft 59 and a link 55 is pivotally connectedwith the arm 64. The link extends to the lower arm of the rocker 39 andis pivotally connected with the rocker. The parts are related so thatthe rocker 39 is substantially vertical or in its neutral position tohold the pawls 42 released when the diaphragms 51 of the bellows 56arein their neutral, unactuated positions;

Means are provided to yieldingly hold the parts in their neutralpositions and to return the parts Any selected or available power meansmay be utilized to operate or move the rocker 39 of the means B. Iprefer to employ a pneumatic means or air motor operated either bypositive or negative pressure, because a means of this nature is lightin weight, inexpensive and easy to service. The preferred form of powermeans C illustrated, embodies a bellows type air motor uti1iz-' totheirneutral positions following each operation. This means includes an arm99 fixed to the vertical shaft 59 of the power means C and a pin 61 onthe'outer part of the arm 55. The arm 65 may be integral with or may beattached to the arm 64. The pin 51 cooperates with convergent faces 99provided on individually pivoted levers or members 59. A spring 19 isconnected substantially vertical. when the shaft 59 is turned throughthe action of the bellows '51 the pin Bl cooperating with the face 68 ofa member 69 pivots that member outwardly against the action of thespring I0. During the return of the shaft 59 and the arm 66 to theoriginal positions the spring restores the member 69 to its normalposition and urges the two faces 58 against the pin Bl to assist in thereturn of the parts and to yieldingly hold the diaphragm 5i and therocker 39 in their neutral positions.

The air motor or power means C further includes a valve mechanismcontrolling the bellows M. A valve chest H is provided in the caseadjacent the bellows 56. The chest II is par-' titioned to have anegative pressure chamber 72, two separate intermediate chambers l3 andan atmospheric pressure chamber 70. The main negative pressure lineextends to and communicates with the chamber 12. A line l5 extends fromeach intermediate chamber 13 to a bellows 58. Ports it connect theatmospheric pressure chamber Ill with the intermediate chambers I3 andports ll are provided to connect the intermediate chambers 13 with thenegative pres Multiple or double valves 10 maintain a static conditionwith the valves IS in the positions where the ports ESL are closed andthe ports ll are open. A valve 82 controls the admission of air to theatmospheric pressure chamber M. A threaded stem 83 may be adjusted tovary the position of the valve 82 and thus regulate the rate ofoperation of the bellows 56.

The control D is operable to control or govern the communication of theindividual diaphragm chambers with the atmosphere. The control D may beresponsive to or operated by directional radio circuits, mercuryswitches, gyroscopes or other directional, stabilizing or coursedetermining and maintaining means. In accordance with the invention thecontrol B includes pipes or line ML and. 84B. each leading from adiaphragm chamber 80 and a valve 85 for controlling the communication ofthese lines with the atmosphere. The lines 84R and 841- are arranged tohave open outer ends in spaced opposition, and the valve 85 has itsactive part between the ends of the lines. The valve 85 is pivoted orsu'pportedfor flexure and is movable from a normal open position'whereboth lines 84R and 84L are open to a position where the line 84R isclosed and the line 84L is open and to a position where the line 84L isclosed and the line 84R is open. The single .valve 85 is thus operableto control the diaphragms I9 of the valves 10 to cause operation ofeither bellows 56. The valve 85 carries an armature or constitutes anarmaof the drawings, embodies a directional radiocircuit control thatgoverns the coils '88 in such amanner that the air craft may beautomatically maintained on a selected course as defined by a radio beamor directional radio broadcast or, in fact, as defined by any radiobroadcast. It is a feature of the invention that the means -D may betuned to be controlled by or to be,

responsive to any available and selected radio broadcast and is notlimited to use with special directional radio beams. .The sensitivemeans or circuit illustrated in Figs. 1 and 2 includes a directional aircraft antenna in the form of a loop 95 which may be provided with atypical Faraday shield 95 for eliminating electrostatic disturbances.The loop 95 has a typical modulated feed or tuned oscillatorycircuit'9'l of a given or fixed frequency and the legs or end leads ofthe loop 95 are connected in a suitable air craft radio compass circuit98. A suitable tunable radio receiver circuit 99 is coupled with theradio compass circuit 98 and with the center tap I of the loop 95. Theradio compass cirsuit 98 has the usual meter 1133 and rectifier tube MllIt'is preferred to fix the loop to the craft and to arrange the loopin aplane transverse of the longitudinal axis of the craft so thatdeviation'of the craft. from its course produces a maximum electron flowfrom the null condition in one side or the other of the rectifier tubeIlll, depending upon the direction of said deviation. A suitable case 9is provided to contain the circuits 9?, 9'8 and 99 and a control panel 8may be provided with the manual control parts and indicators of thecircuits. The circuit 97, the loop 95, the radio receiving circuit 99and the radio compass circuit 98 -may,

of course, be varied greatly indesign and character and the drawingsmerely illustrate a simplified arrangement of these elements. It is tobe understood that the invention is not tobe construed as limited orrestricted to the par- .not necessarily illustrative of preferredcircuits.

The coils 86 of the control D are operated or controlled by the metercircuit of the radio compass circuit 98 through the medium of a relaysystem. This relay system includes two relay tubes I02. The tubes I02have their grids connected with the opposite sides of the meter MI. Therelay system further includes a-suitable power source I03, a common leadI04 from the source I03 and separate leads I05 connected with the coils8B. The power source I03 and the coils 86 may be suitably grounded.Contactor I06 are connected in the power lead I04 and are engageablewith contacts I01 in the coil leads I05 to complete the energizingcircuits to the coils. The contactors I08 are operatedby solenoid coilsI08 connected in'tlie opposite legs of the meter circuit IOI through themedium of the relay tubes I02.

Upon deviation of the craft from its course the loop 95 assumes anon-normal position with respect to the radio beam or radio broadcast,

and an out. of phase condition is produced in the opposite legsoi thecircuit actuating the meter IM and causing electron flow in the tubesI02. Due to the out of phase condition in the rectifier circuit there ispositive D. C. potential with respect to ground in the grid plate of onetube I02 or the other depending uponthe ditive grid which results'in'energization of the solenoid I00 connected with the tube I02 hav-' ingthe positive grid. The energized coil I08 closes its contactor I06 tocause energization ofa coil 80. It will be seen that the deviation ofthe craft from its course causes operation of the valve 85 in onedirection or the other, de-

pending upon the direction of the deviation and the valve 85 is moved ina direction to close a line 84 that actuates the power means C to causethe automatic control or pilot mechanism to move the rudder rod I0 in amanner to correct or compensate for the crafts deviation. The

valve 85 remains actuated or closed-as long as the craft is oil itscourse and the power means C continues to operate so that the controlpart or rudder is intermittently moved until thedc.- viation of thecraft is corrected or compensated .for. When the craft returns to itscourse there is no current flow in the circuit 88 and the circuit to thecoil 86 is opened so that the valve 85 is free to return to its normalposition where bothof the lines 84 are open. This terminates thisoperation of the power means 0.

The means E is provided topartially restore the power means C at the endof'each active movement ofthe tandem bellows 56 so thatthe bellows areconditioned for the active stroke.

reverse a-valve 'IO and cause operation of, the

- power means C.

The relief bleeder valves IIIR and IIIL are adapted to be opened toallow an air flow through their-"respective lines 00R and ML. The lines04R. and ML have branches H03. and IIBL, respectively. The branch I IORof line 04R extends to a point adjacent the valve I I 0L and the branchIIOL of the line L extends to a point adjacent the valve IIOR. Thevalves IIIR and IIIL are operable to seal against the ends of theirrespective branches iIIlR and II8Lto close the same. The valves IIIR andIIIL are provided with spaced arms H9, pivotally supported by spacedpins I projecting from the adjacent supporting plate 33 and suitablelugs I2I on the plate. The pivoted valves IIIR and IIIL areinterconnected with the valves IIOL and OR, respectively. Levers I22 arepivotally supported by pivot pins I23 on the -adjacent supporting plate33 and one end oi each lever I22 is pivotally connected with a stem H5.The other ends of the levers I22 are pivotally connected. with links I24which in turn are pivotally connected the valves IIIR and IIIL.

The means E further includes spring loaded or spring controlled meansfor suddenly operatwith ing or reversing the sets of interconnectedvalves IIOR and IIIL and IIOL and-IIIR. Pairs of spaced connected toggleplates or members I25 are pivoted on the pins I20 that carry the valvesIIIR and IIIL. Extensible tension springs I26 are connected with thevalves I I IR. and II IL and The means E is operated by the power meansC and is interposed in the air lines 84 between the valve 05 and thevalve chest II. preferred structure the means E includes a valve IIORinterposed in the line L, a similar valve IIOL interposed in the-line84R, a valve IIIR. for bleeding or relieving the line 84R and a similarvalve' IIIL for bleeding or relieving the -line L. Fig. 7 bestillustrates the construction of these valves and the manner in whichthey areconnected in the air conduit system.

The valves |IOR and IIOL include casings or hollow bodies II2 eachclosed'at one side by a flexible diaphragm III. The lines 84R and Lcommunicate with the interiors of the valve bodies Illand each line hasa pipe part I whose end projects into a valve body'l I2 to oppose itsdiaphragm III. Stems I I5 are connected to the diaphrag'ms -I I2 andtheir inner ends carry valves I I6. The valves I I0 are preferablypivoted to the stems H5 and to the walls of the bodies H2 and arearranged to closethe ends of the pipe parts H4. Springs II-Iare-connected with the valves II 6 to urge the valves to their-open Inthev The means for pivoting the members I25 to have their outer. endssecured to the adjacent pivoted members I25. The springs I26 areconnected with the members I25 at points spaced some distance from theirpivot pins I20 and are normally at the outer sides of said pins. Thusthesprings I26 are disposed to normally hold the members I25 inpositions where the valves I IR and I I IL are closed. Adjustable stopscrews I2I on the lugs I2I may limit the outward movement of the membersI25 and may position the members where the springs I26 exert a suitableclosing force or holding force on their respective valves ms. and mi..-The toggle members I25 I are adapted to be pivoted inwardly to move thesprings I26 over the pivotal axes of the valves IIIR and IIIL so thatthe springs operate to suddenly open the valves IIIL and IIIR and closethe related or connected valves IIOL and throw or move the springs I20over center will be described below. When a spring I26 is moved over thepivotal center of its respective valve IIIR or II'IL its tension orresiliency suddenly.

moves the valve away from the end of the branch IIO to open the'line Ror 84L, as the case may be, and operates to suddenly move the related orconnected valve I IOL or IIOR. so that the latter closes its respectiveline R or L. The

tripping of a set of valves of the means E, say

.the valves IIOL and IIIR, results in the reversal or operation of thevalves I8 01' the power means C, the latter causing the partial returnof the ber of the valve chest 'II and thus serves to 76 connectedbellows 66 by admitting atmospheric pressure to the bellows ESL and byputting the bellows 56R in communication with the negative pressure line50, so that the bellows may move from their actuated positions towardtheiroriginal neutral positions. Means is provided to return or restorethe toggle members I25, it bein observed that the valves 'IIIR- -IIOLand IIIL- 0B. are restored by their respective springs I20 when themembers I25 return to their normal out positions. The means forrestoring the tog- 'gle members I25 comprise-torsional springs iIZ'l atthe pivot. pins I29 exerting turning forces on the members (see Fig. 4).

The means for pivoting the members I25 to throw or move the springs I26over center includes an arm I28 fixed on the shaft 35. A lever I29 ispivoted between its ends on a pin I39 on the adjacent supporting plate33. A link MI is pivoted to one end of the lever I29 and is connectedwith the arm I28. The connection between the link I3I and the arm I23 isadjustable. In the preferred construction spaced pairs of openings I32are provided in the arm I28 and the link I3I to receive a removable pinI33. The

pin|33 may be arranged in a selected set or pair of openings I32 togivethe link I 3I and lever I29 the desired throw. The means forthrowing-or moving the springs I26 over center further includesa slideI34 disposed between the spaced pairs of connected members I25. A pinI35 on the adjacent plate 33 passes through an elongate slot I36 in theslide I34 and has a head I3'I cooperating wit e slide to preventdisplacement of the $1 e. A pivot pin I33 connects the slide I34 withthe lever I29 so that the slide is shifted longitudinally upon turningof the shaft 35. The pairs of members I 25 are oppositely directed andoppositely facing lugs I39 are provided on the opposite edges of theslide I34 tocooperate with ins I49 on the members I215.

The lugs I39 are split or bifurcated to receive the springs I26. Thesprings I26 pass between the spaced arms H9 and spaced members I25 andmay enter between the side parts of the bifurcated lugs I39 when themembers I25 are in their actuated or in positions' With the valve 85actuated to close one air line. say theline 84R, the valve I8 of therighthand bellows 56R is actuated and the valve I8 of the lefthandbellows is in its normal up position. When the shaft 59 and the rocker39 are being turned by the bellows 56 the slide fI34 moves in the samedirection as the rocker and one of its lugs I39 comes intocooperation-with the pins I49 on the related set of members I25 and thiscooperation pivots or moves the members. This movement of the connectedmembers I 25 continues until the spring I26 moves over the pivotal axisof the members I 25 and the related valve IIIR.- When the spring I26moves over this axis it suddenly pivots the valve II IR downwardly andsuddenlycloses the valve IIOL. Opening of the branch II8R of the line84R and closing of the line 84L reverses the valves III in the valvechest II so that the bellows 56R is put into communication with thenegative pres:- sure.;chamber I and line 59 'and the bellows 56L is putinto communication with the atmosphere.

The tripping of the valves BL and IIIR does i not occur until therighthand pawl of the means B has advanced the ratchet wheel 31 a givendistance. With the valves I8 reversed as just described the bellows 56Lis operated by atmospheric pressure to restore or partially restore theshafts 59 and 35 and the rocker 39. Partial restoration of the shaft 35is accompanied by return movement of the pawl 42, as described above,and by a return movement of the slide I34. As the slide I34 moves backtoward its "original position the torsional spring I26 returns theactuated members I25 and when the members reach a position where thespring I26 passes the pivotal verses the valves IIIR and II 9L so thatthe branch I I311 is closed and the line 94L is opened. This puts thebellows 56R into communication with the atmosphere and puts the bellows56L into communication with the negative pressure chamber I2 and line 59to start the next active stroke of the power means. In the event thatthe valve 85 remains where the line 84R is closed the power means Crepeatedly operates to advance the ratchet-wheel 31 and the aboveoperations are repeated to intermittently move the rudder or control rodI9 in a given direction.

The parts of the means E are related so that the valves NOR and IIIL orII9L and IIIR, as the case may be, are restored to their normalcondition before the slide I34 reaches its original or normal position.This restoration of the valves of the means E before the slide I34 andthe shaft 35-are fully returned stops or limits the return movement ofthe rocker 39 and the rocker stops where its active ratchet dog 81remains in holding cooperation with the ratchet wheel 37 to hold therudder or control rod I9 .against return movement. The means E may beadjusted to vary the stroke of the rocker I34 and the extent ofadvancement of the wheel 37 for each 0peration of the power means C. Thepin I33 may be moved to cooperate with any one of the sets of openingsI32 to have the shaft 35 turn through any selected arc to give the slideI34 its required stroke. In other Words. the adjustment of theconnection between the link I3I and the arm I29 varies the amount ofturning or movement of the shaft 35 and, therefore, varies the amount ofadvancement of the ratchet wheel 3? at each op.- eration of the device.The ratchet wheel 37 may be made to advance th width of one or severalteeth 39 as selected, by making this adjustment.

The means F is a safety control that is readily operated by'the pilot oroperator to disconnect the automatic pilot or control means so that the.

I4I and headed pins I42 on the adjacent plate 33 cooperate with theslots I4l to guide the slide for vertical shifting. A slot I43 intheslide I49 passes the roller pin 46. The stop slide I49 has athickened portion presenting upwardly convergent inclined facesi'l44.Substantially horizontal or transverse upwardly facing shoulders I45 arepr'ovided'at opposite sides of the slide I49. The shoulders I45 are onunthickened-portions of the slide I 40-and preferably slopeupwardly andoutwardly.

The pawls 42 of the means B have parts engageable by the slide I49 torelease the means B or to render the means 3 inactive. Upwardly andoutwardly projecting fingers I46 are provided on center of the valveIIIR. the spring suddenly re- 75 the pawls 42 and each liuger carries astop pin I41. The pins I41 are engageable by the sloping faces I44 ofthe slide I49 when the slide is raised, as will be later described. Theengagement of a pin I41 with a face I44 prevents the related pawl 42from engaging the ratchet wheel 3'! when the rocker 39 is pivoted. Whenthe rocker 39 is pivoted with the slide m in its raised position a pinI41 comes into cooperation with a face I44 and the face acts as a cam orguide to guide the pawl 42 outwardly away from the wheel 31 but does notstop movement of the pawl or the rocker 39. Thus the cooperation of thepins I41 with the faces I 44 does not put a drag or strain on themechanism but serves to prevent advancement of the wheel 31 and therudder rod I when the safety means F is in operation. The stop pins I41are not sufliciently long to cooperate with the shoulders I45 and mayride on the races I44 without engaging the shoulders. Stop pins I48 areprovided on the links SI and are engaged by the shoulders I45 when theslide I40 is raised. with the slide I40 raised to its operative positionthe shoulders I45 engage the pins I46 and thisengagement prevents thedogs 61 from cooperat I ing with the ratchet wheel 31. The pins I46 rideon the shoulders I45 to prevent the springs-'69 from actuating the dogs81.

The means F further includes an effective,

'operation by'the pilot or operator.

instrument panel of the air craft to be imme- A the chamber I66 to thechamber I63 under certain conditions of operation. A port "I con-' nectsthe'chamber I63 with the chamber I64 and a port I12 is adaptedto put thechamber I64 in-communicat'ion with the atmosphere. The valve I60controls the ports Ill and I12 and is operable .by the diaphragm I69.Under normal conditions with the valve I6I closed equal negativepressures exist in the chambers I63 and I66 remote control for the stopslide I40. The remote control includes a double armed lever I49. piv-'otally supported by a pin I50 on a supporting plate 33 (see Fig. 3). Theshort inner-arm of the lever I49 has an operative connection with thevertically shiftable slide I40. In the case illustrated the slide I40has a lateral lug provided with a slot I5I- and a pin I52 on the innerarm of the lever I49 cooperates with the slot I5I to connect the leverand slide. provided for yieldingly holding the slide I40 and the otherelements on the safety means F in their released inactive positions.v Anextensible coiled spring I53 has its upper end connected with a fingerI54 on the inner end of the lever I49 and has its lower end connectedwith a relatively fixed object. In the construction illustrated thelower end of the spring I53 is attached to the pin I46. The spring I53is under tension and normally holds the parts in the retractedpositions, illustrated, with the slide I40 in its lowermost positionspring means is and-the valve I60*is held in the position illustrated bythe. atmospheric pressure acting on the under side-of its upper closureor valve part.

Upon opening of the valve I6I atmospheric pressure is admitted to thechamber I66'to act on the diaphragm. I 69 and this movesthe valve downto the. position where the port I12 is closed and the port "I is open.

The valve I60 is normally in a position where it closes the port I1I andallows free passage of air through the port 112 so that the interior ofthe body I55 is open to the atmosphere.- Thus versed so that the bodyI55 is put into communi-' cation with the negative pressure line I59 andthe diaphragm I56 is operated-to pivot the lever I49 and thus raise thestop slide I40 to its up operative position. The means F is readilyconwhere it does not interfere with the operation of the means B. Thespring I53 is operable to restore the slide I40 and the other elementsof the means F to' their normal positions following operation.

The means F further includes an air motor for operating "the lever I49.The power means for operating the lever I49 may include a hollow bodyI55 having a flexible diaphragm I56 81".

trolled by'the operator or pilot to release the means 13 so that therack II and rudder or control rod I0 are fully freed from the operatingmeans B of the automatic pilot mechanism and the rudder rod may be underthe full control of the manual operating or directing means. The

.the valve I60 is reversed to return to the norinal position illustratedwhere the body I is in communication with the atmosphere. The spring I53returns the slide I40 and the lever I49 to their normal inactivepositions.

the body I55'abo've the diaphragm I56.is vented to the atmosphere. Themeans for operating the diaphragm I56 includes a pipe or line' I69safety means includes branch lines I13 communi-' The invention mayinclude means for render- I ing the power means C inoperative when therod I0and rack II reach predetermined positions at the ends of theirrange of movement. This means is a safety means and is entirelyautomatic. The

cating with the lines 84R and 84L. The branch lines I13 extend to pointsadjacent the rack II.

- The branch lines I13 are normally closed by body I55. The line I59 isunder the control of a master valve I60 which in turn is governed by amanual valve I6I.

The master valve I60 may be similar'to the valves 18 of the power meansC and is arranged in a valve chest I62 associated with the body 156..The chest I62 has a negativepressure chamber I63 with which the line I59communicates, a chamber I64 connected with the interior of the body I55by a line I65, and a chamber I66 under the control of the manual valveI6 I A line I60 passes from the chamber I66 to the valve I6I. The valveI6I may be in the cockpit or at the pivotally or resiliently mountedvalves I14. Longitudinally spaced projections or fingers I15 areprovided on the'rack I I to cooperate with the valves I14.- The fingersI15 are spaced apart and are related to the valves I14 so that onefinger is operable to open the valve I14 ofthe branch line I13communicating with ;the line 8413. when the rack II approaches theextreme end of its movement in one direction and the other finger I15operates to open the valve I14 controlling the branch line of the line041. when'the rack I I reaches the other end of its stroke. The openingof a valve. I 14 admits atmospheric pressure to 85 and thus temporarilyprevents the operationof the power means C. When the rack II returns toa position where it is within its intended range of movement thevalveI14 closes to re-establish operation of the power means C.'

The various elements of the power means C, the means E, the means F andthe associated parts may be contained in the case 3d andthe case ispreferably formed so that it may be opened to render th various partsreadily accessible for servicing, etc.

While the operations of the several means and elements of the automaticpilot have been described above in connection with the detaileddescriptions of the mechanism it is believed that the mode of operationof the device will be better understood from the following descriptionof the general operation of the entire mechanism. In the drawings thecharacters R and L, used as exponents of the reference numerals andassociated with the arrows of direction designate elementsand'directions of movement for effecting movement of the rudder rod orcontrol rod II) for the directing of the craft to the right and left,

respectively. It will be assumed that the craft is in flight and isfollowing a course as defined by a radio beam or radio broadcastand'that the radio receiving circuit 99 is tuned for the reception ofsaid beam or broadcast so that the radio compass circuit 98 is sensitiveto deviations of the craft from 'the beam or broadcast. lit will befurther assumed that the hook 2i is in cooperation with the pin 22 andthat the valve IGI is closed so that the automatic pilot is in operationfor the control of the rod I0. So long as the craft remains on thecourse the parts are in the normal or idle positions illustrated, thevalve 85 and the bellows 56 being neutral and the means B being free orclear-of the ratchet wheel 3'! so that the rudder rod I is free. Thevalves 18 are both normally in the positions illustrated where theinteriors of the bellows 56R and 56L are in communication with thenegative pressure chamber I2 and line 50. x

In the event that the craft deviates from its course because of aircurrent conditions or for other causes the automatic pilot operates tointermittently move the rod III in a direction to compensate for thedeviation and this intermittent operation continues until the planereturns to its course. For example, if the craft deviates to the leftanelectric current is set up in the meter circuit of the radio compassBBto energize a coil I08 and thus close theenergizing circuit to the rightcoil 86. The coil 86 moves the valve 65 so that it closes the line 84R.Closing of the line 84R closes 0115 the chamber 86, associated with thebellows 56R, from the atmosphere to cause reversal of the valve I8 ofthe bellows 56R, the valve I8 moving downwardly by gravity or by theatmospheric pressure acting on the top surface of the valve '18, orboth. When-this occurs the interior of thebellowsSBR is put intocommunication with the atmosphere so that the pressures on theoppositesurfaces of the diaphragm 51 of the bellows are equalized.As-the interior of the bellows 56L remains in communication with thenegative pressure chamber 12 and line 50, the atmospheric pressureacting on the outer surface of the diaphragm 51 of the bellows 56Loperates the tandem bellows. Operation of the bellows 56R and 56L turnsthe shafts 59 and 35 and shifts the slide I34.

Up n urnin of the shaft 35 the rocker 39 swings to engage a dog 81 withthe teeth of the ratchet wheel 31 and then engage a pawl I2 with theratchet wheel to turn the wheel and thus move the rack II and the rodl0. During this operation of the means B a slide lug I 39 pivots itsrelated toggle members I25 and this pivoting of the toggle memberscontinues until the related spring I26 passes over the center of pivotalmovement of the valve IIIR. When this occurs the spring I26 suddenlyopens the valve IIIR and closes the interconnected valve IIIIL. Openingof the valve IIIR reverses the valve I8 of the bellows 56R so that thisbellows is again put into communication with the negative pressurechamber I2 and the line 50. Closing of the valve I IDL reverses thevalve I8 of the bellows 5% so that this bellows is put intocommunication with the atmosphere causing restoring of the bellows 56Rand 56L. This operation of the bellows in a reverse direction moves theshafts 59 and 35 to reverse or restore the means B and the means E.However, the means B and E are only partially restored andthe rocker 39stops before the active dog 81 is released from the ratchet wheel 31.

The restoring operation is terminated before the means B and E are fullyrestored because of the relationship of the lugs I39 and the togglemembers I25. During the restoring cycle the lug I39 engaging theactuated toggle members I moves back sufiiciently to allow the springI21 to pivot the toggle members a distance sufiicient to move the springI26 over the pivotal center of the valve I R before the rocker 39reaches its normal or initial position. When the spring I26 moves overthe pivotal center of the valve' IIIR. it suddenly closes the valve IIIRand opens the valve IIIIL to reverse the valves I8 of the power means 0.Closing of the valve I I IR closes ofi the chamber 86 of the bellows 56Rfrom the atmosphere so that the pressures on the opposite sides of thediaphragm I9 are equalized and the valve I8 moves down by gravity, or bythe atmospheric pressure, or both. Opening of the valve I IEL admitsatmospheric pressure to the chamber 80 of the bellows 56L and thispressure acting on the diaphragm I9 moves the valve I8 up to put theinterior of the bellows 561- into communication with the negativepremure chamber "I2. This reversal of the valves I8 conditions thebellows 56 for another active stroke and the power means C act to turnthe shafts 59 and so that the coils I08 and 85 that have been energizedbecome de-energized. This allows the valve 85 to return to its neutralposition where the lines MR and 8IIL are both open to the atmosphere.With the lines 86R and 84L both open to the atmosphere the bellowsvalves I8 assume their nprmal positions illustrated in Fig. 3 where thebellows R. and ESL are in communication with the negative pressurechamber 12 and line 50 and the power means C is inactive. Upon the laststroke or operation of the power means C immediately following therestoration of the valve 85 to its normal position the bellows 56 returnto their neutral positions under the action of the spring I and thusrestore the means B and E to their normal states. When the means B isrestored to its normal condition the previously active dog-81 is freedfrom the wheel 31 and the pawls 42 are both made inactive. This freesthe rack II and the rudder rod I0.

If at any time during the flight it is desired to disconnect theautomatic pilot from the rudder .rod III the operator or pilot may openthe valve "I. Opening of the valve IGI operates the means F as describedabove, so that the slide I40 is brought to the position where it holdsthe dogs 81 and the pawls 42 against operation. The

means B may be held inoperative by the means' F so long as the valve IGIis open and with the means B thus held inoperative the rack II and therod III are disconnected from the automatic pilot means so thatactuation of the pilot means does not afiect the rudder rod I0. In thecase of an mergency the automatic pilot means may be quicklydisconnected from the rudder rod In by pulling the ring 26 to disengagethe hook 2| from the pin 22. The receiver or receiving circuit 89 is, ofcourse, provided with connections I 90 (see Fig. l), to permit the useof ear phones or the line which may assist the operator in tuning thecircuit, etc.

The pilot means or control means of the present invention has a wideapplicability being useful on vessels, vehicles, conveyances, and craftof many kinds. Accordingly, where I herein employ the term "craft Irefer to air craft, vehicles, ships, carriers, vessels, torpedoes, andconveyances of various natures for use on land and sea and for use inthe air. Where the term "dirigible craft" is employed it refers to anycraft that may be controlled, directed, or steered.

Having described only a typical preferred form and application of myinvention, I do not wish to be limited or restricted to the specificdetails herein set forth, but wish to reserve to myself any thoseskilled in the art or .fall within the scop of the following claims.v

Having described my invention, 1 claim:

l. A control mechanism for a. crafthaving a movable control part, thecontrol mechanism comprising reversible pneumatic power means,intermittent drive means operable by the power means to move said partin either direction, valve means governing the pneumatic means operableto cause actuation of the pneumatic means in either direction,oscillator means interposed between the valve means and the power meansfor producing oscillatory operation of the power means during eachperiod of valve operation, and means for actuating the valve means tocause operation of the pneumatic means in either direction. 1.

2. Means for operating a controlpart of a dirigible craft comprising areversible diiferential fluid pressure power means, an intermittentmovement mechanism operable by the power means for moving said part bysuccessive movement impulses during each operation of the power means,means producing a difierential of pressure for operating the powermeans, valve means either to the right or to the left and for termi-.nating' operation of the power means, a differential pressure meanscontrolling the valve means to cause operation of the power means ineither direction, a line governing the differential pressure means, anda control for said line.

3. Means foroperating a control part of a dlrigible craft comprising areversible power variations or modifications that may appear to meansincluding a pair of bellows connected in tandem, drive means operated bythe power means for moving the control part, a source of negative airpressure, valve means for each bellows controlling the communication ofits respective bellows with the atmosphere and said source of negativepressure, means for controlling the valve means, andlspring detent meansassociated with the power means for restoring the bellows to operation.

4. Means for .operating a control part of a dirigibl'e craft comprisinga reversible power means including two air motor chambers, dianormalwhen the valve means are restored after phragms at the chambers operableby a dif-, ferential in internal and external pressures and comiectedfor movement in unison, means operable by the power means forintermittently mov-' ing the control part in either of two directions,

means conditioned by the power means operable to prevent reversemovement of said part during intermittent advancement of the same ineither direction released upon the return of the diaphragms to theirneutral positions, a control for the power means operable to causeoperation cit the power means in either direction including air linesconnected with the chambers, and means controlling the air lines toprevent the return of the diaphragms to their neutral positions duringoperation of the power means.

5. Means for operating a controlpart of a dirigible craft comprising apneumatic power means operable to produce reciprocable' movement andreversibl to produce active motion in opposite directions, meansoperable by the power means for intermittently moving said control partin opposite directions, .means for restoring the power means to aneutral position at the termina-v tion of a phase of operation in eitherdirection, releasable means put into operation when the power means isoperated to prevent reverse movement of the said part during the returnstrokes of the power means in a plane of its operation and released whenthe power means reaches said neutral position, valve means controllingthe power means, valve operating means operableto retain the valveoperated for substantial periods,

for initiating operation of the power means and means controlling thevalve means to prevent the return of. the power m'eans to its neutralposition so long as said valve operating means is in operation. I

6. Means for operating a control part of -a' dirigible craft comprisinga reciprocable power means, means operated by 'the power means forintermittently moving said'con'trol part; a control for the power means,means tending to'restore the power means to a neutral position,releasable means for preventing reverse movement of the control partduring the reverse strokes of the power means, means acting on saidcontrol to prevent the return of the power means to said neutralpositionwhile the control remains active, .65

' the power means, means acting on said control to prevent the return ofthe power means to said neutral position while the control remainsactive, and remotely controlled means for holding the intermittentmovement means and said releasable to move the control part in eitherdirection,

means normally holding the pawls released from the wheel operable torelease one pawl and restrain the other pawl upon movement of the rockerfrom its neutral position, and means for governing the power means.

9. In a mechanism of the character described for operating a controlpart of a dirigible craft, the combination of, a differential pressurepower means, the power means producing reciprocal motion and beingreversible to have active strokes in either direction, a shaft driven by'the power'means, a rocker secured to the shaft to be oscillated by thepower means, driving means for said control part including a ratchetwheel, pawls on the rocker cooperable with the ratchet wheel to move thecontrol part in either direction, means normally holding the pawlsreleased from the wheel operable to release one pawl and restrain theother pawl upon movement of the rocker from its neutral position, stopdogs for engaging with the wheel to hold it against movement,meansoperated by the rocker normally holding the dogs retracted from thewheel and releasing a dog upon active movement of the rocker in eitherdirection so that the released dog prevents reverse movement of thecontrol part during the return strokes of the power means, and means forgoverning the power means.

10. In a mechanism of the character described for operating a controlpart of a dirigible craft, the combination of, a difierential pressurepower means, the power means producing reciprocal motion and beingreversible to have active strokes in either direction, a shaft driven bythe power means, a rocker secured to the shaft to be oscillated by thepower means, driving means for said control part including a ratchetwheel, pawls on the rocker cooperable with the ratchet wheel to move thecontrol part in either direction, means normally holding the pawlsreleased from the wheel operable to release one pawl and restrain theother pawl upon movement of the rocker from its neutral position, andmeans for governing the power means, the last mentioned means includingregulating means for varying the length of the active strokes of thepower means.

11. In a mechanism of the character described for operating a controlpart of a dirigible craft, the combination of, a difierential pressurepower means, the power means producing reciprocal motion and beingreversible to have active strokes in either direction, a turnable shaftdriven by the power means, an element operatively connected with saidcontrol part to move the same, a ratchet drive between the shaft andsaid element, projections on said element, stop means actuated by theprojections to terminate operation ofthe power means at the oppositeends of the stroke of the element, and a control for the power means.

12. Means for operating a control part of a dirigible craft comprisingan operating mechanism for moving said part comprising a differentialfluid pressure power means reversible to operate in both directions,means operable by the power means to intermittently advance the saidpart in either direction, a control for the power means, and oscillatormeans interposed between the control and power means and operated by thesecond named means for causing oscillatory operation of the power means.

JESS S. MORRISON.

